喷油策略对甲醇/PODEn双燃料压燃燃烧特性的影响  

Effects of fuel injection strategy on combustion characteristics of methanol/PODEn dual-fuel compression ignition mode

作　　者：张鼎成 张光德[1,2] 陈书郅 ZHANG Dingcheng;ZHANG Guangde;CHEN Shuzhi(School of Automobile and Traffic Engineering,Wuhan University of Science and Technology,Wuhan 430081,China;Key Laboratory of Power Machinery and Engineering of Ministry of Education,Shanghai JiaoTong University,Shanghai 200030,China)

机构地区：[1]武汉科技大学汽车与交通工程学院,武汉430081 [2]上海交通大学动力机械与工程教育部重点试验室,上海200030

出　　处：《汽车安全与节能学报》2023年第4期513-520,共8页Journal of Automotive Safety and Energy

基　　金：湖北省自然科学基金(2015CFA113)。

摘　　要：为提高直喷柴油发动机的缸内燃烧效率,降低污染物的排放,研究了不同喷油策略下的甲醇/PODEn混合燃料燃烧、排放特性。基于计算流体动力学(CFD)和仿真分析软件Converge,对某款预混压燃燃烧(PCCI)的直喷柴油发动机进行三维建模;在发动机转速为1200 r/min,在进气压力100kPa、进气温度340.6 K的低负荷初始工况下,进行了仿真计算。结果表明:采用单次喷油时,提前喷油能够大幅提升缸压峰值和比放热峰值,使燃油利用率增加,且主要污染物显著减少;但过早喷油,反应速率加快,污染排放增多。采用2次喷油时,随着预喷时刻的提前,预喷、主喷的正时间隔变长,缸压曲线变化不大;比放热曲线出现2个峰值,峰值略微降低,且喷射时刻(曲轴转角,CA)提前;与各自的质量排放峰值比较,碳烟(Soot)、氮氧化物(NOx)、一氧化碳(CO)的质量排放,分别降低了6.89%、5.41%、23.31%;优化后的预喷、主喷的CA为-27°、-22°。The combustion and emission characteristics of methanol/PODEn mixed fuel under different fuel injection strategies were investigated to improve combustion efficiency and reduce pollutant emissions of a direct injection diesel engine.Based on the Computational Fluid Dynamics(CFD)and simulation analysis software Converge,three-dimensional modeling is carried out for a direct injection diesel engine with a Premixed Compression Combustion Ignition(PCCI)mode.Under the initial low-load conditions of 1200 r/min engine speed,initial pressure of 100 kPa and initial temperature of 340.6 K were calculated.The results show that in a single injection,the peak pressure and the peak specific exothermic is greatly increased at the early injection time,the fuel utilization ratio is increased,and the main pollutants is significantly reduced;But the reaction rate becomes faster and the emission of pollution increases when the injection time is too early.With the advance of the pre-injection time,the interval between the pre-injection time and the main injection time becomes longer,and the cylinder pressure changes little,the heat release rate curve has 2 peaks,the peak value is slightly reduced,and the injection time(crankshaft angle,CA)is advanced.The mass emission of Soot,NOx and CO are decreased by 6.89%,5.41%and 23.31%respectively,compared with each peak value.The pre-injection time and the main injection time of the optimal injection strategy are-27°and-22°.

关 键 词：直喷柴油发动机 预混压燃燃烧(PCCI) 甲醇/PODEn双燃料 喷油策略 燃烧排放特性 燃油利用率 

分 类 号：U463.85[机械工程—车辆工程]